Entertainment Howard Stern costs Mel Gibson's baby-mama $15,000,000

Mel Gibson's baby mama, Oksana Grigorieva, just got word from a California appeals court ... she made one of the worst business decisions in the history of business ... because they just ruled she's only entitled to 1/60 of what she could have gotten from him had she just shut her trap.

The California Court of Appeals just dropped the hammer, saying Oksana screwed herself when she went on Howard Stern in 2013 and claimed domestic abuse at the hands of Gibson. The actor was on the hook for $750,000 -- a settlement he had struck with her -- but had only shelled out $250,000.

I bet she thought, being on Stern would had helped her get high album sales and make her famous like Katy Perry, but instead ...being on Stern didn't help her music career and also screwed herself out of Gibson's money. Oh the irony

Happy for Mel but really, it was worth $15 mil for her to shut up. He has lost mush more than that because of those tapes. Not only has Mel not been hired but two of his Icon releases suffered from the bad press. I guesstimate Mel lost potentially over $50 mil. or more.

And it's hilarious to ask of Howard would make up the difference. Here's a man who sit on his money like a dragon in a cave and doesn't enjoy it.